1. Field of the Invention
The present invention relates to gamma correction for imaging devices, and more particularly to a multiple channel programmable gamma correction generator for imaging devices, such as display panels including LCD TFTs and the like.
2. Description of the Related Art
Imaging devices, including printers or display devices such as CRTs and LCD panels and the like, typically do not respond to input voltage in a linear manner. The luminance or brightness produced by a display device, for example, is not directly proportional to the input signal level, resulting in an overly dark or overly bright image and a nonlinear gray scale. In addition, LCD panels tend to have problems with motion causing the moving display to smear and the dynamic range or contrast ratio to become compressed, further obscuring (e.g., darkening) the image. The nonlinear response of such imaging devices is referred to as “gamma” and is represented as a gamma factor, number or value. If gamma is not compensated, the original image is not accurately reproduced.
Gamma compensation is achieved by applying a gamma correction response that is the inverse of the imaging device response so that the overall system response approaches a more linear transfer function. Manufacturers of imaging products, such as LCD TFT display panels or the like, often incorporate gamma correction to ensure that the original image is reproduced properly. Conventional solutions, however, are typically incorporated on a part-by-part basis, such that the gamma solution integrated into one product line or model is not applicable to another. Programmable gamma devices are known, but are usually implemented for a specific model, or otherwise are implemented using costly discrete devices and/or power-hungry amplifiers.